From "Kounotori" to "X": Cost, Technology, and International Cooperation - The Successful Launch of HTV-X1 Demonstrates the Current State of Japan's Space Logistics

What the Successful Launch Means

On October 26, 2025 (Sunday) around 9 a.m., Japan's new main rocket, the H3 No. 7, lifted off from the Tanegashima Space Center carrying the new unmanned supply ship "HTV-X1." About 14 minutes after launch, it was inserted into the planned orbit, and the flight proceeded smoothly. It is expected to arrive at and be captured by the ISS within a few days. This flight also used the strongest configuration of the H3 (four boosters + large fairing), demonstrating an enhancement in Japan's space transportation capabilities. AP News

Even more significant is the resumption of Japan's supply to the ISS after about five years. This marks a full-fledged return since the retirement of the "Kounotori" (HTV) and is a milestone in restoring Japan's presence as a nation with practical experience in space logistics. The Japan Times

HTV-X1: More Than Just "Transport"

HTV-X1 is a new generation vehicle succeeding the previous HTV (Kounotori), but its capabilities are entirely different. It can carry a larger payload and supply power to the cargo during flight. It supports the transport of samples requiring cold storage and can dock for up to six months after arriving at the ISS. Additionally, after detachment, an extended operation involving about three months of free flight for technology demonstration missions is also envisioned. The most significant update is the expansion of the supply ship's role into a "space experiment platform." AP News

What Was Carried: Inside the Payload

This time, the pressurized section was packed with supply tanks for oxygen, nitrogen, and water, a carbon dioxide removal device, food and consumables, and various experimental devices. The exposed section included the medium-sized exposed experiment adapter "i-SEEP," the ultra-small satellite deployment mechanism "H-SSOD," the small reflector for satellite laser ranging (SLR) "Mt. FUJI," the deployable antenna "DELIGHT," and the next-generation solar cell "SDX," among other experimental/demonstration equipment for use outside the ISS. Details such as the launch time (9:00:15 a.m. Japan time) and "orbital insertion 14 minutes and 4 seconds after separation" were also confirmed. sorae Space Portal Site

The Current Status of the H3 Rocket

The H3 was designed with cost competitiveness in mind as a successor to the H-2A, and its reliability has been gradually honed. After initial issues, it has accumulated successes, including the deployment of defense satellites, and showcased its range with this "strongest configuration" operation. It is becoming an option for Japan in the commercial satellite market, security, and as a key transportation route to the moon and deep space. AP News

Astronaut Yui "Welcomes" the Supply Ship

On the ISS side, Japanese astronaut Kimiya Yui is responsible for capturing the HTV-X1 with the Canadarm2. Before departure, Yui sent a lighthearted message to HTV-X1, saying, "I'm waiting for you! I'll catch you gently!" easing both tension and anticipation. It is understandable that support poured in from fans both domestically and internationally, coinciding with the Sunday morning launch in Japan. The Japan Times

Reactions on Social Media: Celebration, Pride, and Practical Benefits

On X (formerly Twitter), JAXA's official account posted updates on the rescheduled launch time and broadcast information. After the successful launch, replies of congratulations and relief poured in. Many posts had tones like "the strength of domestic rockets," "next to the moon," and "it's exciting that the supply ship becomes an 'experimental mothership,'" suggesting that the "understandability" of technological evolution drove the spread. X (formerly Twitter)

In personal posts, astronaut Yui's posts from the ISS, as an "insider," were symbolic, widely shared for their excitement about the progress of preparations and mentions of HTV-X1. On the media side, Space.com's breaking news and video broadcasts engaged overseas space fans, forming a real-time viewing community. X (formerly Twitter)

YouTube's official live broadcast and JAXA's special page also functioned as hubs, with comments like "the spread of H3's smoke is beautiful" and "the number 14 minutes to orbital insertion is striking," highlighting reactions to the "dual persuasiveness" of visuals and facts. YouTube

Impact on Industry and International Cooperation

This success is not just a one-time flight. The "combination" of a cost-effective launcher and an expandable supply ship not only enhances the reliability of ISS supply but also connects to future commercial stations and lunar orbit bases. For JAXA and manufacturers, it can be a tailwind for proposal activities aimed at overseas customers, and the free flight for technology demonstration is likely to induce new applications (satellite deployment, power experiments, communication demonstrations, etc.). AP News

A Realistic Perspective Toward the "Next"

Of course, the operation of the supply ship truly begins after arrival. The reliable execution of each phase, from capture to docking, long-term berthing, waste collection, and post-detachment demonstration operations, builds trust. If this success supports the expansion of H3's launch slots, the stabilization of the industrial supply chain, and the realization of Japan's "space transportation nation" strategy, HTV-X1 will hold more meaning than just being the first unit. AP News